title: A virophage at the origin of large DNA transposons.
abstract: DNA transposons are mobile genetic elements that have shaped the genomes of eukaryotes for millions of years, yet their origins remain obscure. We discovered a virophage that, on the basis of genetic homology, likely represents an evolutionary link between double-stranded DNA viruses and Maverick/Polinton eukaryotic DNA transposons. The Mavirus virophage parasitizes the giant Cafeteria roenbergensis virus and encodes 20 predicted proteins, including a retroviral integrase and a protein-primed DNA polymerase B. On the basis of our data, we conclude that Maverick/Polinton transposons may have originated from ancient relatives of Mavirus, and thereby influenced the evolution of eukaryotic genomes, although we cannot rule out alternative evolutionary scenarios.
authors.affiliation: Department of Microbiology and Immunology, 1365-2350 Health Sciences Mall, University of British Columbia, Vancouver V6T 1Z3, Canada.
authors.forename: Matthias G
authors.initials: MG
authors.lastname: Fischer
authors.forename: Curtis A
authors.initials: CA
authors.lastname: Suttle
mesh_terms: D000595:Amino Acid Sequence; D004251:DNA Transposable Elements; D004267:DNA Viruses / Q000235:genetics* / Q000502:physiology*; D004279:DNA, Viral / Q000235:genetics; D004259:DNA-Directed DNA Polymerase / Q000235:genetics; D019143:Evolution, Molecular; D016679:Genome, Viral; D019426:Integrases / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012526:Satellite Viruses / Q000235:genetics* / Q000502:physiology*; D058009:Stramenopiles / Q000821:virology; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics; D014779:Virus Replication
chemical_list: D004251:DNA Transposable Elements; D004279:DNA, Viral; D014764:Viral Proteins; D019426:Integrases; D004259:DNA-Directed DNA Polymerase